Method for growing titanium dioxide on tube wall of quartz tube and titanium dioxide quartz tube

Abstract

The invention belongs to the technical field of photocatalytic purification of water resources, and particularly relates to a method for growing titanium dioxide on the wall of a quartz tube and a titanium dioxide quartz tube. According to the method, titanium dioxide grows on the inner wall of a quartz tube in a chemical bonding mode, and then metal oxide is loaded. Titanium dioxide and loaded metal oxide on the obtained titanium dioxide quartz tube are firmer and not prone to falling off, and the quartz tube can be recycled. The technical problem that in an existing preparation method, a titanium dioxide structure of a prepared titanium dioxide quartz tube is prone to falling off is solved. In addition, after the titanium dioxide quartz tube provided by the invention is loaded with a metal oxide, not only is the generation of photocatalytic active substances improved, but also the forbidden bandwidth is reduced. According to the present invention, with the quartz tube, the organic pollutants in the solution can be degraded, and the pollutants in the air can be degraded due to the sealing property of the quartz tube, such that the dual degradation functions of the liquid and the gas can be achieved, and the performance of the catalyst can be used in the diversified manner.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocatalytic water purification, and further relates to a titanium dioxide quartz tube used for photocatalytic water purification and a method for growing titanium dioxide on the wall of the quartz tube. Background Art

[0002] Titanium dioxide quartz tubes are formed by loading titanium dioxide onto quartz tube walls. Under ultraviolet light, titanium dioxide quartz tubes can degrade organic pollutants. Furthermore, metal oxides can be loaded onto these tubes to create loaded titanium dioxide quartz tubes. Loaded titanium dioxide quartz tubes not only enhance the production of photocatalytically active species but also reduce the band gap, enabling more efficient use of sunlight.

[0003] Currently, methods for loading titanium dioxide onto quartz tube walls include the dip-coating method and the spin-coating method. Both methods involve impregnating or coating a titanium dioxide sol onto the quartz tube wall, followed by high-temperature calcination. However, the titanium dioxide structure of these titanium dioxide-loaded quartz tubes is prone to detachment.

[0004] To increase the specific surface area, titanium dioxide quartz tubes are typically loaded with metal oxides by depositing metal oxide powders. However, metal oxides easily fall off during use, making them difficult to recycle and reuse, significantly increasing the burden on catalytic pollutant degradation. Summary of the Invention

[0005] The present invention addresses the technical problem of "the titanium dioxide structure of the prepared titanium dioxide quartz tube easily falling off" in existing titanium dioxide quartz tube preparation methods. Specifically, the method involves growing titanium dioxide on the quartz tube wall. This method results in a Si-O-Ti bond between the titanium dioxide and the inner wall of the quartz tube, effectively growing the titanium dioxide on the tube wall. Consequently, the titanium dioxide in the titanium dioxide quartz tube obtained using this method is not easily detached during use, and the titanium dioxide quartz tube can be recycled for repeated degradation of organic pollutants.

[0006] One of the purposes of the present invention is to provide a new method for growing titanium dioxide in a quartz tube, that is, a new method for growing titanium dioxide on the wall of a quartz tube. The wall of the quartz tube is usually the inner wall of the quartz tube.

[0007] The method for growing titanium dioxide on the wall of a quartz tube comprises the following steps:

[0008] (1) The quartz tube is activated and then cleaned with deionized water until the cleaning solution is neutral and dry;

[0009] (2) a water film liquid is brought into contact with the wall of the quartz tube treated in step (1) so that the wall of the quartz tube is loaded with a water film; the water film liquid is composed of hexadecyltrimethylammonium bromide (CTAB), deionized water, and an organic solvent;

[0010] (3) the reaction liquid is brought into flow contact with the wall of the quartz tube treated in step (2); the reaction liquid is composed of tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol and an organic solvent;

[0011] (4) The quartz tube treated in step (3) is allowed to stand at 80-150° C., and then calcined at 450-550° C. to obtain a titanium dioxide quartz tube.

[0012] In step (1), the main purpose of activating the quartz tube is to open the hydroxyl groups inside the quartz tube and expose more silanol groups. An acidic or alkaline solution can be used as an activation solution to treat the quartz tube wall to activate the hydroxyl groups on the inner surface of the quartz tube; wherein the activation solution can be a sodium hydroxide solution of any concentration. The specific operation can be: injecting the activation solution into the quartz tube so that the activation solution is in full contact with the inner wall of the quartz tube, and leaving it for a period of time for activation.

[0013] In step (1), the activation time can be 2-3 hours. If the activation time is too short, the silanol groups on the inner wall of the quartz tube will not be fully opened. If the activation time is too long, the quartz tube will be corroded. In addition, the required activation time is related to the concentration of the activation solution; the higher the concentration of the activation solution, the shorter the required activation time.

[0014] In step (1), the drying temperature may be 120±10° C. and the drying time may be 1-2 hours. Excessively long drying time may easily cause the inner wall of the quartz tube to be contaminated by other substances in the oven.

[0015] In step (2), the contact time between the water film liquid and the wall of the quartz tube treated in step (1) is too short and may lead to insufficient growth, while too long and time-consuming and labor-intensive. Therefore, the contact time is preferably 1-2 hours.

[0016] In response to the technical problem of "the titanium dioxide film in the prepared titanium dioxide quartz tube is uneven due to the influence of gravity" during the experiment, the present application successfully solved this problem by improving the experimental plan and placing the quartz tube in step (2) vertically, so that the water film liquid flows and grows in the vertically placed quartz tube. Therefore, as a preferred solution, the quartz tube treated in step (1) is placed vertically.

[0017] In step (2), the CTAB surfactant is used to make the water film more uniform, and deionized water is used to prevent hydrolysis from being affected by other ions. A low combined volume fraction of CTAB and deionized water in the water film solution will result in uneven water film coverage, while a high combined volume fraction will easily cause water droplets to agglomerate and fall off. Therefore, preferably, the combined volume fraction of CTAB and deionized water is 8-12%. For ease of operation, CTAB is preferably prepared into a saturated solution with deionized water.

[0018] In step (2), the organic solvent is a water-soluble organic solvent. n-Butanol has a moderate water solubility and can better release water molecules to form a water film. Therefore, n-Butanol can be selected as the organic solvent.

[0019] In step (3), the reaction liquid is in fluid contact with the wall of the quartz tube treated in step (2); the presence of a water film on the inner wall of the quartz tube causes tetrabutyl titanate to hydrolyze on the inner wall of the quartz tube to generate titanic acid, which grows on the surface of the quartz tube via Si-O-Ti bonds. As a preferred embodiment, the reaction liquid is in fluid contact with the wall of the quartz tube treated in step (2) for 2-3 hours.

[0020] In step (3), the ethyl orthosilicate provides silanol groups that dehydrate and condense with the titanium hydroxyl groups of titanic acid to continue forming Si-O-Ti bonds. Because the silanol groups inside the quartz tube are only present on the surface, the presence of the ethyl orthosilicate crosslinker allows the titanium dioxide film grown on the surface of the quartz tube to continue growing, promoting the continuous formation of the titanium dioxide film and thus preventing cracks.

[0021] In step (3), the polyethylene glycol is used as a pore-forming agent. In this step, the polyethylene glycol is attached to the surface of the quartz tube. After calcination, the polyethylene glycol on the inner wall of the quartz tube will decompose on its own to form a porous structure, which provides convenience for the subsequent loading of metal oxides. Even if metal oxides are not required to be loaded in the later stage, polyethylene glycol still needs to be added in this step. The reason is that the polyethylene glycol decomposes to form a porous material, which can enhance the catalytic degradation performance of the titanium dioxide quartz tube. The molecular weight of the polyethylene glycol is 400-2000; preferably, the molecular weight of the polyethylene glycol is 800-1500.

[0022] In step (3), the reaction solution is prepared by mixing tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and an organic solvent in a volume ratio of 9-12:6-9:9-12:100. The organic solvent is a water-soluble organic solvent, and the organic solvent may be n-butanol.

[0023] In step (4), the quartz tube treated in step (3) is allowed to stand at 80-150°C for a period of time to volatilize the organic solvent on the inner surface of the quartz tube; the standing time may be 1-2 hours. The tube is then calcined at 450-550°C in a nitrogen atmosphere to form anatase-type titanium dioxide on the inner wall of the quartz tube, and polyethylene glycol is decomposed to form a porous structure on the inner wall surface of the quartz tube, thereby obtaining a titanium dioxide quartz tube; the calcination time may be 2-3 hours.

[0024] The titanium dioxide quartz tube obtained in step (4) can also be further treated to obtain a titanium dioxide quartz tube loaded with metal oxides. Specifically, the process can include step (5): soaking the quartz tube treated in step (4) in a metal nitrate of any concentration for 10-15 minutes, drying it at 100-140°C, and then calcining it at 450-550°C in a nitrogen atmosphere for 2-3 hours to decompose the nitrate, thereby obtaining a titanium dioxide quartz tube loaded with metal oxides; preferably, the metal is cerium and / or copper. In actual operation, the concentration of the metal nitrate aqueous solution can be 0.1-0.2 mol / L.

[0025] The inner diameter of the quartz tube is 1-1.5 mm and the wall thickness is ≤1 mm. Preferably, the length of the quartz tube is ≥50 cm. The quartz tube used in the present invention has a small inner diameter and wall thickness, which can fully contact the organic pollutants to be degraded and has high light transmittance.

[0026] The specific scheme of the above-mentioned method for growing titanium dioxide on the wall of a quartz tube comprises the following steps:

[0027] Step 1: inject sodium hydroxide solution into the quartz tube and let it stand for 2-3 hours to activate the inner wall of the quartz tube;

[0028] Step 2: Clean the inner wall of the quartz tube with deionized water until the solution in the quartz tube becomes neutral, dry it at 110-130°C for 1-2 hours, and then remove it for later use;

[0029] Step 3: Add CTAB saturated aqueous solution to n-butanol solvent at a volume fraction of 8-12% as a water film liquid, then place the quartz tube vertically and allow the water film liquid to circulate in the quartz tube for 1-2 hours to grow a water film;

[0030] Step 4: Tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and an organic solvent are prepared into a reaction solution in a volume ratio of 9-12:6-9:9-12:100, and the reaction solution is circulated in a quartz tube for 2-3 hours to allow the tetrabutyl phthalate to fully react and hydrolyze with the water film in the quartz tube;

[0031] Step 5: The quartz tube treated in step 4 is allowed to stand at 80-150° C. for 1-2 hours to evaporate the organic solvent on the inner surface of the quartz tube; then, it is calcined at 450-550° C. for 2-3 hours in a nitrogen atmosphere to form anatase-type titanium dioxide on the inner wall of the quartz tube, and polyethylene glycol is decomposed to form a porous structure on the inner wall surface of the quartz tube, thereby obtaining a titanium dioxide quartz tube;

[0032] Step 6: Soak the quartz tube calcined in step 5 in a 0.1-0.2 mol / L metal nitrate aqueous solution for 10-15 minutes, then dry it at 100-140°C; repeat the soaking and drying operations to increase the loading amount; then calcine it at 450-550°C in a nitrogen atmosphere for 2-3 hours to decompose the nitrate to obtain a titanium dioxide quartz tube loaded with metal oxide.

[0033] A second object of the present invention is to provide a titanium dioxide quartz tube.

[0034] The titanium dioxide quartz tube is prepared by the method described in one of the objectives of the invention and is a quartz tube with titanium dioxide growing on the inner wall surface, or a quartz tube with metal oxide loaded and titanium dioxide growing on the inner wall surface.

[0035] The third object of the present invention is to provide an application of the titanium dioxide quartz tube described in the second object of the invention for degrading organic matter. The titanium dioxide quartz tube can be used to degrade MB (methylene blue) and the like.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The method of the present invention can allow titanium dioxide to be bonded to the inner wall of the quartz tube in the form of Si-O-Ti, and titanium dioxide is grown on the inner wall of the quartz tube by chemical bonding. The titanium dioxide grown in this way is more firm and not easy to fall off, and the quartz tube is also easy to recycle.

[0038] A quartz tube with titanium dioxide is grown and then loaded with metal oxides. The loaded metal oxides are firm and not easy to fall off, which not only increases the production of photocatalytically active substances, but also reduces the band gap and reduces the recombination of photogenerated current-carrying electrons on titanium dioxide, which has a positive effect on the degradation of methylene blue.

[0039] This experiment solved the problem of uneven film thickness caused by gravity when the quartz tube was placed horizontally by coating the vertical fluidity of the quartz tube with titanium dioxide, and provided a new preparation method for growing titanium dioxide on the inner wall of the quartz tube.

[0040] The titanium dioxide quartz tube loaded with metal oxides prepared by the present invention can degrade organic pollutants in a solution. Due to the airtightness of the quartz tube, it can also be used to degrade pollutants in the air, achieving dual degradation functions of liquid and gas and utilizing the performance of the catalyst in a more diversified manner.

[0041] The whole degradation process of the present invention is simple, economical and cost-effective, can be reused many times, and is easy to achieve mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the XRD pattern of the titanium dioxide quartz tube loaded with metal oxides prepared in Example 1;

[0043] Figure 2 This is an electron micrograph of the inner wall of a titanium dioxide quartz tube loaded with metal oxides prepared in Example 1;

[0044] Figure 3 This is an electron micrograph of the inner wall of the titanium dioxide quartz tube loaded with metal oxides prepared in Example 1 after six degradation cycles;

[0045] Figure 4 This is an electron microscope image of the titanium dioxide quartz tube loaded with metal oxide prepared in Example 2.

[0046] In the figure, 1 is the inner wall of the quartz tube, and 2 is the titanium dioxide film loaded with metal oxides. DETAILED DESCRIPTION

[0047] The present invention will be described in detail below with reference to specific drawings and embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0048] The reagents used in the following examples are all commercially available products.

[0049] Example 1

[0050] Step 1: Prepare the following materials: a quartz tube, sodium hydroxide, n-butanol, tetraethyl orthosilicate, polyethylene glycol (molecular weight 1000), tetrabutyl phthalate, CTAB (cetyltrimethylammonium bromide), cerium nitrate, copper nitrate, and deionized water. The quartz tube should be 50 cm long, 1.5 mm inner diameter, and 1 mm thick.

[0051] Step 2: Prepare a sodium hydroxide solution with a concentration of 1 mol / L, inject the prepared sodium hydroxide solution into a quartz tube and place it for two hours for activation.

[0052] Step 3: clean the inner wall 1 of the quartz tube with deionized water until the solution in the quartz tube becomes neutral, put it in an oven, dry it at 120° C. for 1 hour, and then take it out for use.

[0053] Step 4: Prepare a saturated aqueous solution of CTAB with deionized water. Add this saturated CTAB solution to a 10% volume fraction in n-butanol to form the water film solution. Then, clamp the quartz tube upright in a test tube rack. Circulate the water film solution within the tube for one hour to grow the water film.

[0054] In step 5, the solution in the quartz tube with the water film formed is drained. A uniform water film can be observed on the inner wall 1 of the quartz tube. A reaction solution is then prepared using a volume ratio of 3:2:3:32 between tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and n-butanol. As in step 4, the reaction solution is circulated within the quartz tube for two hours to allow the tetrabutyl phthalate to fully react and hydrolyze with the water film within the quartz tube.

[0055] Step 6: Place the reacted quartz tube in an oven at 120°C for one hour, and then calcine it in a muffle furnace at 500°C for two hours.

[0056] Step 7, soak the quartz tube calcined in step 6 with 0.1mol / L Ce(NO3)3 and 0.2mol / L Cu(NO3)2 (the volume ratio of the two is 1:1) solution for ten minutes, and then dry it at 120℃; repeat the soaking and drying operation 4 times to increase the loading amount, and then calcine it at 500℃ in a nitrogen atmosphere in a tube furnace for 2h; obtain a titanium dioxide quartz tube loaded with metal oxides, and its XRD pattern is as follows Figure 1 As shown in the electron microscope image Figure 2 shown.

[0057] Figure 2 In the embodiment, a titanium dioxide film is grown on the inner wall 1 of the quartz tube, and a metal oxide is loaded on the titanium dioxide film; wherein the thickness of the titanium dioxide film 2 loaded with the metal oxide is uniform.

[0058] Step 8: inject 10 ppm of methylene blue into the prepared titanium dioxide quartz tube loaded with metal oxides, and degrade the tube under irradiation of ultraviolet light (5W). The degradation lasts for 45 minutes, and the degradation rate is 94%.

[0059] Degradation rate calculation method: Debug the standard curve of the UV-visible spectrophotometer, test the absorbance of the solution in the quartz tube at fixed intervals, and draw a degradation curve. Calculate the degradation rate using the formula. The formula used is:

[0060] The titanium dioxide quartz tube loaded with metal oxides prepared in this embodiment was subjected to six degradation experiments according to step 8, and then the inner wall of the titanium dioxide quartz tube loaded with metal oxides after six degradations was observed by electron microscopy; the electron microscopy images are as follows: Figure 3 shown. Figure 3 In the experiment, the titanium dioxide film loaded with metal oxides on the inner wall of the quartz tube did not fall off.

[0061] Example 2

[0062] Step 1: Prepare the following materials: a quartz tube, sodium hydroxide, n-butanol, tetraethyl orthosilicate, polyethylene glycol (molecular weight 1000), tetrabutyl phthalate, CTAB, cerium nitrate, copper nitrate, and deionized water. The quartz tube has a length of 50 cm, an inner diameter of 1.5 mm, and a wall thickness of 1 mm.

[0063] Step 2: Prepare a sodium hydroxide solution with a concentration of 1 mol / L, inject the prepared sodium hydroxide solution into a quartz tube and place it for two hours for activation.

[0064] Step 3: clean the inner wall 1 of the quartz tube with deionized water until the solution in the quartz tube becomes neutral, put it in an oven, dry it at 120° C. for 1 hour, and then take it out for use.

[0065] Step 4: Prepare a saturated aqueous solution of CTAB. Add 10% by volume of the prepared CTAB solution to n-butanol solvent to form the water film solution. Place the quartz tube horizontally and allow the solution to sit for one hour to grow a water film.

[0066] In step 5, the solution in the quartz tube with the water film grown therein is poured out. A water film can be seen evenly attached to the inner wall of the test tube. A reaction solution is then prepared according to a volume ratio of 3:2:3:32 between tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and n-butanol. The reaction solution is injected into the quartz tube, which is then placed horizontally. The reaction solution grows inside the quartz tube, allowing the tetrabutyl phthalate to fully react and hydrolyze with the water film inside the quartz tube.

[0067] Step 6: Place the reacted quartz tube in an oven at 120° C. for one hour, and then calcine it in a muffle furnace at 500° C. for two hours to obtain a titanium dioxide quartz tube.

[0068] Step 7, soak the quartz tube calcined in step 6 with 0.1mol / L Ce(NO3)3 and 0.2mol / L Cu(NO3)2 (the volume ratio of the two is 1:1) solution for ten minutes, and then dry it at 120℃; repeat the soaking and drying operation 4 times to increase the loading amount, and then calcine it at 500℃ in a nitrogen atmosphere in a tube furnace for 2h; obtain a titanium dioxide quartz tube loaded with metal oxides; its electron microscope image is as follows Figure 4 shown. Figure 4 In the embodiment, the thickness of the metal oxide-supported titanium dioxide thin film 2 is non-uniform.

[0069] Example 3

[0070] Step 1: Prepare the following materials: a quartz tube, sodium hydroxide, n-butanol, tetraethyl orthosilicate, polyethylene glycol (molecular weight 1000), tetrabutyl phthalate, CTAB, cerium nitrate, copper nitrate, and deionized water. The quartz tube has a length of 50 cm, an inner diameter of 1.5 mm, and a wall thickness of 1 mm.

[0071] Step 2: Prepare a sodium hydroxide solution with a concentration of 1 mol / L, inject the prepared sodium hydroxide solution into a quartz tube and place it for two hours for activation.

[0072] Step 3: clean the inner wall 1 of the quartz tube with deionized water until the solution in the quartz tube becomes neutral, put it in an oven, dry it at 120° C. for 1 hour, and then take it out for use.

[0073] Step 4: Prepare a saturated aqueous solution of CTAB. Add the prepared saturated aqueous solution of CTAB to n-butanol at a volume fraction of 10% to form the water film solution. Then, clamp the quartz tube vertically in a test tube rack. Circulate the water film solution within the tube for one hour to grow the water film.

[0074] In step 5, the solution in the quartz tube with the water film formed is drained. A uniform water film can be observed on the inner wall 1 of the quartz tube. A reaction solution is then prepared using a volume ratio of 3:3:3:32 between tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and n-butanol. The reaction solution is circulated within the quartz tube for two hours to allow the tetrabutyl phthalate to fully react and hydrolyze with the water film.

[0075] Step 6: Place the reacted quartz tube in an oven at 120°C for one hour, and then calcine it in a muffle furnace at 500°C for two hours.

[0076] Step 7, soak the quartz tube calcined in step 6 in a solution of 0.1 mol / L Ce(NO3)3 and 0.2 mol / L Cu(NO3)2 (the volume ratio of the two is 1:1) for ten minutes, and then dry it at 120°C; repeat the soaking and drying operations 4 times to increase the loading amount, and then calcine it at 500°C in a nitrogen atmosphere in a tubular furnace for 2 hours; obtain a titanium dioxide quartz tube loaded with metal oxides.

[0077] The titanium dioxide quartz tube loaded with metal oxides prepared in this embodiment was subjected to six degradation experiments according to step 8 of Example 1, and then the inner wall of the titanium dioxide quartz tube loaded with metal oxides after six degradations was observed by electron microscopy; the electron microscopy images were similar to those in FIG. Figure 3 approximate.

[0078] Example 4

[0079] Step 1: Prepare the following materials: a quartz tube, sodium hydroxide, n-butanol, tetraethyl orthosilicate, polyethylene glycol (molecular weight 1000), tetrabutyl phthalate, CTAB, cerium nitrate, copper nitrate, and deionized water. The quartz tube has a length of 50 cm, an inner diameter of 1.5 mm, and a wall thickness of 1 mm.

[0080] Step 2: Prepare a sodium hydroxide solution with a concentration of 1 mol / L, inject the prepared sodium hydroxide solution into a quartz tube and place it for two hours for activation.

[0081] Step 3: clean the inner wall 1 of the quartz tube with deionized water until the solution in the quartz tube becomes neutral, put it in an oven, dry it at 120° C. for 1 hour, and then take it out for use.

[0082] Step 4: Prepare a saturated aqueous solution of CTAB. Add the prepared saturated aqueous solution of CTAB to n-butanol at a volume fraction of 10% to form the water film solution. Then, clamp the quartz tube vertically in a test tube rack. Circulate the water film solution within the tube for one hour to grow the water film.

[0083] In step 5, the solution in the quartz tube with the water film formed is drained. A uniform water film can be observed on the inner wall 1 of the quartz tube. A reaction solution is then prepared using a volume ratio of 3:2:4:32 between tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and n-butanol. The reaction solution is circulated within the quartz tube for two hours to allow the tetrabutyl phthalate to fully react and hydrolyze with the water film.

[0084] Step 6: Place the reacted quartz tube in an oven at 120°C for one hour, and then calcine it in a muffle furnace at 500°C for two hours.

[0085] Step 7, soak the quartz tube calcined in step 6 in a solution of 0.1 mol / L Ce(NO3)3 and 0.2 mol / L Cu(NO3)2 (the volume ratio of the two is 1:1) for ten minutes, and then dry it at 120°C; repeat the soaking and drying operations 4 times to increase the loading amount, and then calcine it at 500°C in a nitrogen atmosphere in a tubular furnace for 2 hours; obtain a titanium dioxide quartz tube loaded with metal oxides.

[0086] The titanium dioxide quartz tube loaded with metal oxides prepared in this embodiment was subjected to six degradation experiments according to step 8 of Example 1, and then the inner wall of the titanium dioxide quartz tube loaded with metal oxides after six degradations was observed by electron microscopy; the electron microscopy images were similar to those in FIG. Figure 3 approximate.

[0087] Example 5

[0088] Step 1: Prepare the following materials: a quartz tube, sodium hydroxide, n-butanol, tetraethyl orthosilicate, polyethylene glycol (molecular weight 1000), tetrabutyl phthalate, CTAB, cerium nitrate, copper nitrate, and deionized water. The quartz tube has a length of 50 cm, an inner diameter of 1.5 mm, and a wall thickness of 1 mm.

[0089] Step 2: Prepare a sodium hydroxide solution with a concentration of 1 mol / L, inject the prepared sodium hydroxide solution into a quartz tube and place it for two hours for activation.

[0090] Step 3: clean the inner wall 1 of the quartz tube with deionized water until the solution in the quartz tube becomes neutral, put it in an oven, dry it at 120° C. for 1 hour, and then take it out for use.

[0091] Step 4: Prepare a saturated aqueous solution of CTAB. Add the prepared saturated aqueous solution of CTAB to n-butanol at a volume fraction of 10% to form the water film solution. Then, clamp the quartz tube vertically in a test tube rack. Circulate the water film solution within the tube for one hour to grow the water film.

[0092] In step 5, the solution in the quartz tube with the water film formed is drained. A uniform water film can be observed on the inner wall 1 of the quartz tube. A reaction solution is then prepared using a volume ratio of 4:2:3:32 between tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and n-butanol. The reaction solution is circulated within the quartz tube for two hours to allow the tetrabutyl phthalate to fully react and hydrolyze with the water film.

[0093] Step 6: Place the reacted quartz tube in an oven at 120°C for one hour, and then calcine it in a muffle furnace at 450°C for two hours.

[0094] Step 7, soak the quartz tube calcined in step 6 in a solution of 0.1 mol / L Ce(NO3)3 and 0.2 mol / L Cu(NO3)2 (the volume ratio of the two is 1:1) for ten minutes, and then dry it at 120°C; repeat the soaking and drying operations 4 times to increase the loading amount, and then calcine it at 500°C in a nitrogen atmosphere in a tubular furnace for 2 hours; obtain a titanium dioxide quartz tube loaded with metal oxides.

[0095] The titanium dioxide quartz tube loaded with metal oxides prepared in this embodiment was subjected to six degradation experiments according to step 8 of Example 1, and then the inner wall of the titanium dioxide quartz tube loaded with metal oxides after six degradations was observed by electron microscopy; the electron microscopy images were similar to those in FIG. Figure 3 approximate.

[0096] Example 6

[0097] Step 1: Prepare the following materials: a quartz tube, sodium hydroxide, n-butanol, tetraethyl orthosilicate, polyethylene glycol (molecular weight 1000), tetrabutyl phthalate, CTAB, cerium nitrate, copper nitrate, and deionized water. The quartz tube has a length of 50 cm, an inner diameter of 1.5 mm, and a wall thickness of 1 mm.

[0098] Step 2: Prepare a sodium hydroxide solution with a concentration of 1 mol / L, inject the prepared sodium hydroxide solution into a quartz tube and place it for two hours for activation.

[0099] Step 3: clean the inner wall 1 of the quartz tube with deionized water until the solution in the quartz tube becomes neutral, put it in an oven, dry it at 120° C. for 1 hour, and then take it out for use.

[0100] Step 4: Prepare a saturated aqueous solution of CTAB. Add the prepared saturated aqueous solution of CTAB to n-butanol at a volume fraction of 10% to form the water film solution. Then, clamp the quartz tube vertically in a test tube rack. Circulate the water film solution within the tube for one hour to grow the water film.

[0101] In step 5, the solution in the quartz tube with the water film formed is drained. A uniform water film can be observed on the inner wall 1 of the quartz tube. A reaction solution is then prepared using a volume ratio of 3:2:3:32 between tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol, and n-butanol. This solution is circulated within the quartz tube for two hours to allow the tetrabutyl phthalate to fully react and hydrolyze with the water film.

[0102] Step 6: Place the reacted quartz tube in an oven at 120°C for one hour, and then calcine it in a muffle furnace at 550°C for two hours.

[0103] Step 7, soak the quartz tube calcined in step 6 in a solution of 0.1 mol / L Ce(NO3)3 and 0.2 mol / L Cu(NO3)2 (the volume ratio of the two is 1:1) for ten minutes, and then dry it at 120°C; repeat the soaking and drying operations 4 times to increase the loading amount, and then calcine it at 500°C in a nitrogen atmosphere in a tubular furnace for 2 hours; obtain a titanium dioxide quartz tube loaded with metal oxides.

[0104] The titanium dioxide quartz tube loaded with metal oxides prepared in this embodiment was subjected to six degradation experiments according to step 8 of Example 1, and then the inner wall of the titanium dioxide quartz tube loaded with metal oxides after six degradations was observed by electron microscopy; the electron microscopy images were similar to those in FIG. Figure 3 approximate.

[0105] Comparative Example 1

[0106] The titanium dioxide quartz tube is prepared by adopting the existing gel sol method.

[0107] (1) 10 ppm of methylene blue was injected into the quartz tube and degraded under ultraviolet light (5W). The degradation time was 45 minutes and the degradation rate was 90%.

[0108] pass Figure 2 and Figure 4 From the comparison, it can be concluded that: compared with the quartz tube placed horizontally, the thickness of the metal oxide-loaded titanium dioxide film 2 of the titanium dioxide quartz tube prepared by vertical fluidity coating when the quartz tube is placed vertically is more uniform.

[0109] The titanium dioxide quartz tube prepared by the method of the present invention has a titanium dioxide film loaded with metal oxides, which has a high degree of adhesion to the inner wall of the quartz tube, is more firm, and can be recycled repeatedly.

Claims

1. A method for growing titanium dioxide on the wall of a quartz tube, characterized in that: The method comprises the following steps: (1) The quartz tube is activated and then cleaned with deionized water until the cleaning solution is neutral and dry; (2) a water film liquid is brought into contact with the wall of the quartz tube treated in step (1) so that the wall of the quartz tube is loaded with a water film; the water film liquid comprises hexadecyltrimethylammonium bromide, deionized water, and an organic solvent; (3) the reaction liquid is brought into flow contact with the wall of the quartz tube treated in step (2); the reaction liquid is composed of tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol and an organic solvent; (4) The quartz tube treated in step (3) is allowed to stand at 80-150°C and then calcined at 450-550°C.

2. The method according to claim 1, wherein In step (1), Treating the quartz tube wall with an acidic or alkaline solution for activation; preferably, an alkaline solution is used for activation; more preferably, the alkaline solution is a sodium hydroxide solution; or / and, The activation time is 2-3h.

3. The method according to claim 1, wherein In step (2), The water film liquid is in flow contact with the wall of the quartz tube treated in step (1) for 1-2 hours; or / and, The total volume fraction of hexadecyltrimethylammonium bromide and deionized water in the water film liquid is 8-12%; or / and, The organic solvent is a water-soluble organic solvent, preferably n-butanol.

4. The method according to claim 3, wherein The quartz tube treated in step (1) is placed vertically.

5. The method according to claim 1, wherein In step (3), The reaction solution is in flow contact with the wall of the quartz tube treated in step (2) for 2-3 hours; or / and, The reaction solution is prepared by mixing tetrabutyl titanate, ethyl orthosilicate, polyethylene glycol and an organic solvent in a volume ratio of 9-12:6-9:9-12:100; or / and, The organic solvent is a water-soluble organic solvent, preferably n-butanol.

6. The method according to claim 1, wherein In step (4), The standing time is 1-2 hours; or / and, The calcination time is 2-3h.

7. The method according to claim 1, wherein The method further comprises the following steps: the quartz tube treated in step (4) is soaked in metal nitrate for 10-15 minutes, then dried at 100-140°C, and then calcined at 450-550°C in a nitrogen atmosphere for 2-3 hours; preferably, the metal is cerium and / or copper.

8. The method according to claim 1, wherein The inner diameter of the quartz tube is 1-1.5 mm and the wall thickness is ≤1 mm.

9. Titanium dioxide quartz tube, characterized in that The titanium dioxide quartz tube is prepared by the method according to any one of claims 1 to 8.

10. Use of the titanium dioxide quartz tube according to claim 9 for degrading organic matter.

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